An artist's impression of what could be the first moon outside our solar system ever found, via NASA’s Hubble and Kepler space telescope observations. (Credit: L. Hustak/NASA/ESA/)

Over the last couple of decades, astronomers have identified thousands of planets outside our solar system. However, they have been unable to find confirmation of a moon revolving around any of the distant worlds, mainly because the generally smaller satellites are harder to spot. Now, some researchers from Columbia University believe they have found evidence of an alien moon orbiting a gaseous exoplanet which, lies almost 8,000 light years away.